Author’s Note: This article is a sister article to Your Maximum Muscular Bodyweight and Measurements. The equations presented in this article outline a level of development beyond the capabilities of the vast majority of trainees, including most champions.

If you have any questions or criticisms concerning this article, please post them on The Strength and Size Forum so I’ll have a permanent record of them on this site. But please keep in mind that I didn’t “set” these “limitations”, or intend to imply that they are absolutes, I merely analyzed the existing data.

If you sign up for The Strength and Size Forum you will be required to use your real full name as your Display Name …we like to keep it mature and accountable here.

When I wrote my first article dealing with muscular potential almost five years ago I had no idea the interest, opposition and even anger it would spark [1]. As a friend of mine once said, “Reality is an animal few want to face, so we have to call it a negative, to be avoided at all costs.” On the other hand, quite a few people have expressed relief at what they’ve described as a “breath of fresh air”. In any case, I’m surprised at how much interest the subject of muscular potential has sparked.

Actually, no one can claim to be able to predict a person’s muscular potential by simply looking at them or taking a few measurements. There are far too many variables to consider, many of which are unknown, to allow such an assessment. However, statistically, it is possible to predict the point which you are likely never to surpass. That may or may not be your personal potential limit, but it is infinitely more likely that your potential is less than this prediction than it is greater.

How many times do we hear of someone claiming to have surpassed the development of the world’s greatest drug-free bodybuilders? Of course, they seldom word it like that, but they make the claim nonetheless. You know the type: The internet guy who has 19.5″ arms but won’t show his picture or tell his real name. And if you do see a photo it’s always of some guy with over 20% body fat (sorry, but a fat 18+” arm doesn’t count) and/or an obvious “chemical dependency” that you won’t satisfy at GNC. Or how about the friend someone knows who bench presses over 500 pounds and squats 900 in his basement. Of course, you’ll never see him do it but you’re supposed to believe it nonetheless.

In truth, during my 18-year involvement with the Iron Game I have seen some 500-pound benchers and 800+ pound squatters. I know them reasonably well and trained with them and alongside them. They do exist and they are undeniably genetically super-gifted, impressive specimens but, almost universally, they’re on anabolic/androgenic drugs and they carry way too much fat to even dream of getting on a bodybuilding stage. And if they dieted down to true single-digit body fat levels I can practically guarantee none of the drug-free guys would surpass the development of bodybuilding’s greatest natural champions of similar height and bone structure …perhaps a seemingly strong statement to make, but the purpose of this article is to take an honest look at what is reality and what is just locker room B.S.

My previous works with regards to muscular potential have been criticized because I used bodybuilders as my reference group. The argument has been presented that natural bodybuilders are not necessarily the group with the greatest potential for building muscle mass. American football players, rugby players and powerlifters often have the potential for even greater muscle gains, or so I’m told. And in my opinion, that is quite probably true. Bodybuilders do not necessarily carry the most lean body mass [2]. However, no group carries more muscle mass at such low body fat levels than do bodybuilders. Muscle mass is quite simply the bodybuilder’s specialty. No group attains lean body part measurements as great as elite-level bodybuilders …at least not with respect to frame size. And finally, nobody really cares about such things except bodybuilders and bodybuilding judges anyway. So, if you’re reading this I assume you are a bodybuilder (or an aspiring bodybuilder) and have no interest in comparing yourself to rugby players or anyone else other than yourself and fellow bodybuilders. Why should you?

Setting the bar

Muscular dimensions of elite-level bodybuilders are positively correlated with height and joint circumferences [3-6]. Of course, individual muscular potential is determined by a host of factors such as fiber-type distribution, muscle belly lengths, tendon insertion points, anabolic and catabolic hormonal profiles, etc., but the general rule is: The bigger the man the bigger the muscles he can potentially develop. But human hormonal profiles being what they are (the average male serum testosterone level is between 2.7 and 10.7 ng/ml) only so much muscle can be built and maintained without the use of exogenous anabolic drugs …even by a genetic anomaly.

The muscular development of natural bodybuilding champions is the closest reference we have to indicate the upper limit of drug-free muscle mass potential. These men possess naturally high testosterone levels, full muscle bellies, and the host of other characteristics that permit the development of world-class physiques. And if the sample group is large enough from which these champions are selected then, statistically, we can set bounds on a person’s likelihood of exceeding these champions’ achievements.

For instance, in my observation of thousands of drug-free bodybuilders over the past 18 years the largest lean arms I know of, built without the assistance of drugs are/were 2.53 times wrist circumference. In terms of stature, the largest arms I know of are/were 0.27 times height. These statistics were achieved by bodybuilding champions known for outstanding arm development that easily surpasses that of their fellow competitors in terms of relative arm size. Considering the fact that a random sample of thousands of trainees would, with almost certainty, produce nobody of superior development (how many drug-free people do you know with such development in lean condition?) we can make a statistically rigorous statement: If these genetic wonders have superior arm development than a random sample of 9513 experienced bodybuilding trainees (which they most certainly do …and more) and there are 1000000 experienced bodybuilders on Earth, then 95% of the total population would be unable to develop arms even 1% in excess of these champions. If a random sample of 16317 experienced bodybuilding trainees cannot surpass these champion’s achievements (which also is likely considering these are world champions with the most superior arm development selected from over 50 years’ worth of drug-free champions), then it can be said that 99% of the world’s total training population would not be able to exceed these predictions by even 1%. You can see where this is going.

So, as upsetting as it may be to some people, I can say with near certainty that your potential for muscular arm size will be less than this.
So how big can a person get?

I am going to assume that you want to build a body with aesthetic proportions. Only one man I mentioned in my brief arm example above was a major physique champion. The other developed huge arms by largely neglecting the rest of his body and developing clearly disproportionate arms. Even the man who did win a major physique title was on the verge of having arms that are “too big”. In fact, he drastically reduced his arm training efforts because he himself feared they were becoming disproportionate to the rest of his body.

For each major body part I selected the top elite-level bodybuilders possessing the greatest muscular measurements with respect to height and bone structure (as indicated by wrist and ankle circumferences). Keep in mind that these bodybuilders were in relatively lean conditions when these measurements were taken and also possessed a degree of muscular proportion sufficient to win them high-level titles. That way I minimized the influence of high levels of body fat and avoided trainees who obsessively trained individual muscles but were unable to achieve such development in other muscle groups. Nobody in history has achieved superior development in every muscle group, so this was necessary to keep the application of the findings at least somewhat realistic for the training population. Actually, it’s probably not realistic to assume you have the potential to equal what I am about to give you, but at least it can help you set some goals and let you know where you stand in relation to the best.

Scaled for height and bone structure (as indicated by wrist and ankle circumferences) the bodybuilders with the greatest arm development relative to their frame size had/have a biceps measurement approximated by the following equation: biceps = 1.1709W + 0.1350H. Where, biceps = upper arms measured flexed, around largest point, W = Wrist circumference measured on the hand side of the styloid process (the styloid process is the bony lump on the outside of your wrist) and H = Height. All measurements are taken in inches.

Statistically, your chances of surpassing them are almost nil. Is that a defeatist attitude? Not at all! It’s merely raising or lowering the bar (depending on your current preconceptions about drug-free bodybuilding) to where it belongs. On the other hand, who’s to say that you can’t achieve something similar – after all these men are/were only human. Consider it a challenge rather than a limitation, but keep things in the proper perspective.

Similarly, I performed a fit of the top bodybuilders with respect to each body part. The largest relative chest measurement I am aware of (as it happens, taken prior to 1954 and the introduction of anabolic steroids into bodybuilding [7,8]) belonged to Reg Park …probably due not only to his great pec and back musculature but also his deep rib cage. If any elite-level, drug-tested bodybuilder thinks they might have surpassed this level of development please contact me with verifiable statistics and I will update this formula: chest = 1.625W + 1.3682A + 0.3562H. I don’t expect that I’ll be updating any time soon.

Even with today’s standard of increasing leg size the largest muscular thighs I have been able to verify on champion-level natural bodybuilders are approximated by the following equation: thighs = 1.4737A + 0.1918H. Where A = ankle circumference (in inches) at the smallest point. But please keep in mind that even relatively small changes in body fat level can significantly increase thigh circumference – lots of people can surpass the measurements this equation gives when their legs are fat. Again, if you exceed this prediction in lean condition and have a similar level of development throughout the rest of your physique please contact me with your verifiable statistics.

* W = Wrist circumference measured on the hand side of the styloid process.(The styloid process is the bony lump on the outside of your wrist.)
* A = Ankle circumference at the smallest point
* H = Height in inches

forearms – fist clenched, hand out straight, measured at largest point

neck – below Adam’s apple at smallest point

thighs – standing relaxed, midway between hip and knee

calves – standing relaxed, at largest point

* For all measurements tape should be snug but not compressing the flesh.

For the average trainee of 5’10″ tall with 7.25″ wrists and 9.25″ ankles the equations yield:

chest = 1.625 x 7.25 + 1.3682 x 9.25 + 0.3562 x 70 = 49.4″

biceps = 1.1709 x 7.25 + 0.1350 x 70 = 17.9″

forearms = 0.950 x 7.25 + 0.1041 x 70 = 14.2″

neck = 1.1875 x 7.25 + 0.1301 x 70 = 17.7″

thighs = 1.4737 x 9.0 + 0.1918 x 70 = 27.1″

calves = 0.9812 x 9.0 + 0.1250 x 70 = 17.6″

Depending on how unrealistic or realistic your expectations are, those numbers may seem way too low, or ridiculously high. If you’ve never used steroids and have been training seriously for more than five years (and have actually gotten lean enough to see your abs) then you probably think your predictions are unattainable. If, on the other hand, you’re a beginner who reads the muscle magazines showcasing heavy steroid-users then you’re probably shocked and calling me a quack about now. Hey, either way, I didn’t impose these “maximums”, I just did the analysis of them.

Is it really realistic to think that these equations predict your muscular potential? Well, honestly, no. These equations represent the achievements of some of the drug-free bodybuilding world’s greatest champions. A quick glance at Table 1 will show that none of the listed champions attained all of the predictions in each of their body parts. Statistically, it’s very unlikely that you will achieve any of the measurements, in lean condition (i.e. with visible abs), that the equations predict for you. But even if only one in a thousand people will reach that level, how do you know that person is not you unless you try? Someone will indeed surpass these predictions. Maybe the same person will even surpass them all. Might that person be you? No one knows for sure.

But if the predictions do seem discouragingly high to you, see my article Your Maximum Muscular Bodyweight and Measurements. That article outlines a similar 6-year study I did on champion bodybuilders and the achievements of drug-free versus drug-using bodybuilders in general. The formulae in that article outline what your balanced championship physique would measure based, again, on drug-free champions both past and present, but are more realistic than the specially selected “maximums” presented here.

And what of the internet “big guys” who claim to be lifetime drug-free and are 265 pounds at 8% body fat with 20″ arms? Well, all I can say is get onstage and raise the bar for us all. And if you get a chance you can join me for a workout in my basement …I’ll need a spot for my 500 pound bench presses.